In 1923, the United States Supreme Court heard United States v. Bhagat Singh Thind, a landmark case that exposed the arbitrary and pseudo-scientific nature of racial classification in American law. Bhagat Singh Thind, an Indian Sikh who served in the U.
S. Army during World War I, applied for naturalized citizenship under the Naturalization Act of 1906, which restricted citizenship to free white persons and persons of African descent. Thind argued that as a high-caste Hindu, he was classified as Caucasian by contemporary scientific and anthropological definitions, which traced the Aryan language family back to northern India.
Just three months prior, in Ozawa v. United States, the Court had ruled that a Japanese applicant was not white because he was not Caucasian. However, when faced with Thind's flawless scientific argument for being Caucasian, Justice George Sutherland pivoted completely.
The Court unanimously ruled that white did not mean Caucasian in a scientific sense, but rather referred to whiteness as understood by the common man. This moving goalpost stripped Thind and dozens of previously naturalized Indian-Americans of their citizenship, highlighting how racial legal categories were engineered specifically to exclude non-European immigrants regardless of scientific logic.